蒸汽吞吐分采同抽水平井工作参数优化
发布时间：2019-06-21 07:03
【摘要】：目前,水平井蒸汽吞吐是国内外各油田开发稠油油藏的重要方法,但是在实际的油田开发过程中,水平井筒内的流体存在一定的压差,使得水平井筒内的流体从趾端流向跟端,同时沿水平井筒生产方向也有流体不断地从地层流入,这就是一种变质量流动过程,而且井筒内的流动和油藏渗流之间相互影响、相互作用。在水平井笼统采油过程中,水平井筒的两端是存在一定压力差的,在稀油井或含水较高的油井,沿水平井筒长度方向的压力降通常都是很小的,基本可以忽略不计。但是对于高粘度长距离水平段的油井,水平井筒内可能会产生较大的压力降,这种压降最终的结果可能是跟部生产压降高于端部,使得流体不均匀地沿井眼流动,即使在均质地层中,这种压差(即根部-端部效应)也会存在,即油井根部动用较好,但是在生产一段时间后出现水锥或气锥现象,最终导致油井的生产寿命过早结束,在油井水平段的端部留下大量的剩余油。为了实现水平井段油层的均匀泄油,本文提出了水平井分采同抽的方案,即在水平井的水平段中下入中心管,将中心管和水平段环形空间各自作为独立的液流通道进行开采。但是,对于采取分抽方案后水平段压降变化规律及其对油井流入动态的影响仍不明确。因此,有必要研究地层深处向井流动及水平井井筒内的流动特性,为后续抽汲参数的优化设计提供理论依据。本文首先从基本的质量、动量和能量守恒方程出发,以油水两相流理论为依据,充分考虑井壁摩擦、加速损失以及液流混合干扰等造成的压降,建立了水平井井筒流动压降计算的数学模型;同时以两相渗流力学理论为基础,推导出了水平井在油藏中产生的势,建立了水平井地层稳定渗流方程,确定水平井井筒的流入动态模型;根据压力的连续性、质量体积平衡条件,并利用温度的能量守恒方程把井筒模型和油藏模型连接起来建立耦合模型,并用VB语言编制了计算程序并导入到MATLAB软件对压降分布规律进行了描述。通过对比加中心管前后压降的变化规律,优化了中心管的最优距离以及管径等的参数。最终得到:若水平井筒长度为100m时,加中心管后其产量比未加中心管产量增加约0.8~1.05m3/d,中心管管径4cm,下入长度118m为最优,能使增产效果达到最大,增产量约为2 m3/d。,并且选取杜84大-H1井进行抽汲参数的优选。最终选择管式泵中的整体泵筒,泵径为70mm,泵的柱塞面积为38.48cm2,联接油管外径为88.9mm,联接抽油杆螺纹直径为30.163mm,通过查找抽油机技术规范,选择抽油机型号为CYJY14-6-89HB。
[Abstract]:At present, horizontal well steam huff and puff is an important method to develop heavy oil reservoirs at home and abroad, but in the actual oil field development process, there is a certain pressure difference in the fluid in the horizontal wellbore, which makes the fluid in the horizontal wellbore flow from the toes to the following end, and at the same time, there is a continuous inflow of fluid from the formation along the production direction of the horizontal wellbore, which is a process of variable mass flow. Moreover, the flow in wellbore and reservoir seepage interact and interact with each other. In the general production process of horizontal wells, there is a certain pressure difference at both ends of the horizontal wellbore. In dilute wells or wells with high water cut, the pressure drop along the direction of horizontal wellbore length is usually very small, which can be ignored. However, for oil wells with high viscosity and long distance, there may be a large pressure drop in the horizontal wellbore. The final result of this pressure drop may be that the pressure drop of the heel production is higher than that of the end, so that the fluid flows inevenly along the wellbore, and even in the homogeneous formation, the pressure difference (that is, the root-end effect) exists, that is, the root of the oil well is used well, but the phenomenon of water cone or gas cone occurs after a period of production. Finally, the production life of the oil well ends prematurely, leaving a large amount of remaining oil at the end of the horizontal section of the well. In order to realize uniform oil discharge in horizontal well section, a scheme of horizontal well production and pumping is put forward in this paper, that is, the central pipe and horizontal annular space are exploited as independent liquid flow channels in the horizontal section of horizontal well. However, it is still unclear about the variation of pressure drop in the horizontal section and its influence on the inflow performance of the oil well after the pumping scheme is adopted. Therefore, it is necessary to study the flow characteristics from deep formation to well and in horizontal wellbore, so as to provide theoretical basis for the optimization design of swabbing parameters. In this paper, based on the basic conservation equations of mass, momentum and energy, based on the theory of oil-water two-phase flow, the pressure drop caused by wellbore friction, accelerated loss and mixed interference of liquid flow is fully considered, and the mathematical model for calculating the flow pressure drop of horizontal well wellbore is established. At the same time, based on the theory of two-phase seepage mechanics, the potential of horizontal well in reservoir is deduced, the stable seepage equation of horizontal well formation is established, and the inflow dynamic model of horizontal well bore is determined. According to the continuity of pressure and the condition of mass volume balance, the wellbore model and reservoir model are connected by the energy conservation equation of temperature to establish the coupling model, and the calculation program is compiled with VB language and introduced into MATLAB software to describe the distribution law of pressure drop. By comparing the variation law of pressure drop before and after adding the central tube, the parameters of the optimal distance and diameter of the central pipe are optimized. Finally, if the horizontal wellbore length is 100m, the output of the central tube is increased by about 0.8 脳 1.05m3 / d, the diameter of the central pipe is 4cm, and the down-entry length is 118m, which can maximize the increase of production and increase the production of about 2m3 鈮，
本文编号：2503885
[Abstract]:At present, horizontal well steam huff and puff is an important method to develop heavy oil reservoirs at home and abroad, but in the actual oil field development process, there is a certain pressure difference in the fluid in the horizontal wellbore, which makes the fluid in the horizontal wellbore flow from the toes to the following end, and at the same time, there is a continuous inflow of fluid from the formation along the production direction of the horizontal wellbore, which is a process of variable mass flow. Moreover, the flow in wellbore and reservoir seepage interact and interact with each other. In the general production process of horizontal wells, there is a certain pressure difference at both ends of the horizontal wellbore. In dilute wells or wells with high water cut, the pressure drop along the direction of horizontal wellbore length is usually very small, which can be ignored. However, for oil wells with high viscosity and long distance, there may be a large pressure drop in the horizontal wellbore. The final result of this pressure drop may be that the pressure drop of the heel production is higher than that of the end, so that the fluid flows inevenly along the wellbore, and even in the homogeneous formation, the pressure difference (that is, the root-end effect) exists, that is, the root of the oil well is used well, but the phenomenon of water cone or gas cone occurs after a period of production. Finally, the production life of the oil well ends prematurely, leaving a large amount of remaining oil at the end of the horizontal section of the well. In order to realize uniform oil discharge in horizontal well section, a scheme of horizontal well production and pumping is put forward in this paper, that is, the central pipe and horizontal annular space are exploited as independent liquid flow channels in the horizontal section of horizontal well. However, it is still unclear about the variation of pressure drop in the horizontal section and its influence on the inflow performance of the oil well after the pumping scheme is adopted. Therefore, it is necessary to study the flow characteristics from deep formation to well and in horizontal wellbore, so as to provide theoretical basis for the optimization design of swabbing parameters. In this paper, based on the basic conservation equations of mass, momentum and energy, based on the theory of oil-water two-phase flow, the pressure drop caused by wellbore friction, accelerated loss and mixed interference of liquid flow is fully considered, and the mathematical model for calculating the flow pressure drop of horizontal well wellbore is established. At the same time, based on the theory of two-phase seepage mechanics, the potential of horizontal well in reservoir is deduced, the stable seepage equation of horizontal well formation is established, and the inflow dynamic model of horizontal well bore is determined. According to the continuity of pressure and the condition of mass volume balance, the wellbore model and reservoir model are connected by the energy conservation equation of temperature to establish the coupling model, and the calculation program is compiled with VB language and introduced into MATLAB software to describe the distribution law of pressure drop. By comparing the variation law of pressure drop before and after adding the central tube, the parameters of the optimal distance and diameter of the central pipe are optimized. Finally, if the horizontal wellbore length is 100m, the output of the central tube is increased by about 0.8 脳 1.05m3 / d, the diameter of the central pipe is 4cm, and the down-entry length is 118m, which can maximize the increase of production and increase the production of about 2m3 鈮，
本文编号：2503885
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